Coronary Sinus Catheterization Technique for Studying Coronary Blood Flow and Myocardial Metabolism in vivo.

Abstract

The following technique permits the sampling of coronary venous blood and the measurement of coronary blood flow in the intact dog by the nitrous oxide method: A standard i.v. catheter (size 7-9F), inserted through the dog''s external jugular vein under light nembutal anesthesia, is directed into the coronary sinus under fluoroscopic control. The coronary sinus ostium lies just anterior to the inferior vena caval opening, and the sinus curves abruptly medially and to the left along the posterior a-v groove. The somewhat hazardous injn. of diodrast will outline much of the coronary venous system, because of abundant veno-venous anastomoses. In normal dogs weighing 28-75 lbs., mean blood O2 contents were: coronary sinus, 3.8 Vol. %; mixed venous blood, 12.5; femoral artery, 16.9. Dogs recovered promptly unless purposely sacrificed. 30 autopsies on sacrifice sometimes showed significant endocardial damage after coronary sinus catheterization, but even more damage after pulmonary artery catheterization. Myocardial and coronary damage from sinus obstruction was only avoided by gently inserting a small catheter only 1-2 cm. into the sinus for only 60 min. These precautions are being used in similar current studies in man, in whom all catheterization procedures appear to carry much less hazard. The dog''s normal coronary blood flow in vivo ranges from 70-100 ml./100 g. of heart/min.